By Graham K. Rogers

The idea of security for a personal computer is anathema for many users. While some workers in an ofice may use a password, it may be so simple or so widely known within the office that its effect is diminished. Many eschew passwords completely, either through laziness or ignorance. In many cases, the security of a computer depends on the store it was bought from or the friend who set it up initially. Keycard uses proximity sensing to lock the computer when the user is away from the device, so this may appeal to some.

Security Ignored

In the case where passwords are used, these may be less effective because of their simplicity. The most common passwords in use are "password," "123456," and "12345678 (Chenda Ngak, CBS).

In this part of the world many Macs arrive in their owners' hands with the main account named Apple and the return/enter key as password. The return key is a data entry, and is ASCII 13 on most systems. Trying to use this as password on a Mac will generate a warning, but does not stop this being used.

When creating an account, a ? (question mark) icon beside the password box opens a utility that will generate passwords in a number of ways. The helpful CodePoetry site has a utility available that opens this when required.

But this is too much for many users, who just want to start the computer and work (or play). Security starts with recognising potential problems then deciding to act.

On my Macs, the password is required when the screen is blank, a screensaver is working or if the computer is asleep. I usually move the cursor to a "Hot Corner" (System Preferences > Desktop & Screensaver) and the computer is secure. I write, Usually, as a surprise visit, an urgent student request or another unexpected event may cause me to leave the computer unattended for longer than I intended. Although the screensaver is set to come on within 2 minutes, it may be too late by then.

Solutions

Proximity sensing is a useful trigger to lock or unlock devices and thus provide security in a passive manner (once the system is set up), making it easier for users and safer for those unplanned absences. The wifi project activates when the device is within range of the receiver; the RFID system activates when the device is out of range

While my students are experimenting with RFID and Wi-Fi, the short distances that Bluetooth specifications work within, are also suitable for activation or deactivation. Software from Appuous (a US developer) has recently become available lock a Mac when the device it is linked to is no longer within the range of the Blutooth.

The application, Keycard, is available on the Mac App Store for $6.99 and is used with the iPhone or iPad, although "Any Bluetooth enabled device" may be used (the information on the developer site tells us).

Keycard - Office iMac

Activation is quite straightforward. Clicking on the menubar icon reveals a small panel with an iPhone icon (showing connected or not), a slider for locking and two controls: an Off switch which quits the app; and a gear icon. When this is clicked at the top are boxes for a four digit code. To the left of this is an icon that toggles on visibility: off, we only see dots when the code is entered; on, we can see the numbers.

Blow the code panel, any devices paired are listed. There is also a button marked Add a new Device. When this is pressed, it seeks out any Bluetooth enabled devices and these are added. Although I went backwards and forwards between the iPad and iPhone at home later, it would see both devices for the purposes of connection, but only one device at a time could be used as the security trigger.

I walked out of my office carrying the iPhone which I left with a technician. When I came back, there was a semi-transparent screen over the desktop asking for the 4-digit code. This is used in case the phone is lost in some way. I retrieved my phone and went back into the office: the computer was ready for me to use. At that initial stage I did not leave it for long enough for any screen-saver activation.

When I later tried the application on the MacBook Pro at home, I found that the screensaver did not operate at all when the iPhone was within range of the computer. If I wanted this, or the screen to go off, it had to be done manually with hot corners.

Keycard - MacBook Pro

Installation was straightforward and when I started the app it appeared as before. Pairing the app with the iPhone was not as easy, but the MacBook Pro and this iPhone have never been the best of friends when using Bluetooth.

I had an early chance of testing it when the Pizza arrived and I had to go down 9 floors. Friends in the apartment reported that the screen had appeared as I had predicted. I was later able to see this myself from the kitchen, only a couple of metres away, so perhaps there was some signal shielding from the concrete.

The same happened a couple of hours later when I was working in one room and the iPhone was being charged in another. This time, however, there was a nuisance factor as the security screen kept appearing and disappearing. The distance I had the phone away from the computer was just enough for the signal to be intermittent. Perhaps because of this, when I typed the security code in to clear the screen, the numbers were not accepted as they had been before. When the screen did clear for a moment, I quit the app.

Comments

In some environments this may be less useful and users would be better served by a security routine: use of password and screen-saver security. The office is another matter entirely and a user is more likely to keep the iPhone on the person (in a pocket or bag) so moving away from the computer would operate the Keycard security as designed. In a home, we tend to leave the phone lying around (charging, or in the bedroom perhaps having changed clothes).

With Bluetooth active on the MacBook Pro and the iOS device (either the iPhone or iPad), battery life may be affected. The iMac was not affected as this operates on mains power only.

Keycard could be a useful alternative in situations where the password is not normally used. The first step, however, is for users to be aware of security and the risks that an unattended computer may cause.

Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs.